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SQL left join vs multiple tables on FROM line?
... Employee.DepartmentID
Note that the last one there is an inner join, in order to fulfill the criteria that you only want departments with people.
Ok, so what happens now. Well, the problem is, it depends on the database engine, the query optimizer, indexes, and table statistics. Let me explain.
...
SQL standard to escape column names?
... SQLite,
'foo' is an SQL string
"foo" is an SQL identifier (column/table/etc)
[foo] is an identifier in MS SQL
`foo` is an identifier in MySQL
For qualified names, the syntax is: "t"."foo" or [t].[foo], etc.
MySQL supports the standard "foo" when the ANSI_QUOTES option is enabled.
...
Practical uses for AtomicInteger
...two main uses of AtomicInteger:
As an atomic counter (incrementAndGet(), etc) that can be used by many threads concurrently
As a primitive that supports compare-and-swap instruction (compareAndSet()) to implement non-blocking algorithms.
Here is an example of non-blocking random number generator...
What is compiler, linker, loader?
...telligent than an assembler. It checks all kinds of limits, ranges, errors etc. But its program run time is more and occupies a larger part of the memory. It has slow speed. Because a compiler goes through the entire program and then translates the entire program into machine codes. If a compiler ru...
How to use CMAKE_INSTALL_PREFIX
...(should be /foo/bar/bubba
-- The C compiler identification is GNU 4.4.7
-- etc, etc,...
CIP = /usr/local (should be /foo/bar/bubba
CIP = /foo/bar/bubba (should be /foo/bar/bubba
-- Configuring done
-- Generating done
Second run
CIP = /foo/bar/bubba (should be /foo/bar/bubba
CIP = /foo/bar/bubba (...
Revert a range of commits in git
...nius. thanks. It hadn't occurred to me I need to revert commits in reverse order for the patches to apply, duh. This command shows the way.
– Tim Abell
May 15 '12 at 14:20
5
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Tool to generate JSON schema from JSON data [closed]
...ema, that I can rework manually, adding things like description, required, etc, which can not be infered from the specific examples.
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How to use the 'sweep' function
...by FUN.
For instance, if you want to add 1 to the 1st row, 2 to the 2nd, etc. of the matrix you defined, you will do:
sweep (M, 1, c(1: 4), "+")
I frankly did not understand the definition in the R documentation either, I just learned by looking up examples.
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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...ical: should the row names be in ascending (FALSE) or in descending (TRUE) order?
#' @param coldecreasing logical: should the col names be in ascending (FALSE) or in descending (TRUE) order?
#' @param default_value numeric: default value of matrix entries if no value exists in data.frame for the ent...
PHP DOMDocument loadHTML not encoding UTF-8 correctly
...u have multi-byte characters (such as Chinese, Russian, Arabic, Hebrew, ...etc.)
I recommend reading this article: http://coding.smashingmagazine.com/2012/06/06/all-about-unicode-utf8-character-sets/. You will understand how UTF-8 works and why you have this problem. It will take you about 30 minu...